Re: [PATCH 0/6] arm64: ti: Use syscon for the Control Module

[Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>]

Hi Andrew,

On 29/05/2026 01:59, Andrew Davis wrote:
> On 5/28/26 7:53 AM, Tomi Valkeinen wrote:
>> I have been trying to get BeagleY-AI display support to upstream:
>>
>> 20260513-beagley-ai-display-v2-0-9e9bcefde6bc@ideasonboard.com
>>
>> One difficulty has been the handling of the Control Module region, as
>> we need access to a single in that region, surrounded by registers for
>> other subsystems. In my series I made the related node a syscon, thus
>> allowing versatile access to the registers:
>>
>> https://lore.kernel.org/all/20260513-beagley-ai-display- 
>> v2-14-9e9bcefde6bc@ideasonboard.com/
>>
>> However, that's not a correct way to handle it. I realized we already
>> have ti,j721e-system-controller.yaml binding for older SoCs, which has
>> syscon but it's not used for the newer TI SoCs. This series takes the
>> same binding into use for the newer SoCs.
>>
> 
> We moved away from this system-controller thing because it was always
> a hack to allow us to poke into random control registers from nodes
> throughout the DT. This was a mess and also caused issues with multiple
> mappings to the same registers (some sub nodes inside the control space
> also make their own mappings). If you need access to registers then make
> a node with those registers in the `reg` property.

Like in this patch (dss_dpi0_clk_ctrl)?

https://lore.kernel.org/all/20260420-beagley-ai-display-v1-14-f628543dfd14%40ideasonboard.com/

My understanding is that that's NACKed, as we end up adding new syscon 
compats and syscon nodes for (possibly many) single register blocks.

  Tomi